Allow me to be a contrarian. My reasoning has nothing to do with East v. West, but rather judgment.
A pilot's duties require judgment and someone who has shown really bad judgment, especially in the work environment, should not be a pilot. This is the same poor judgment equation that was present in the case of the AWA pilots in Miami and a number of other occurrences elsewhere.
Absent any proof that the gun magically fired itself during descent to CLT I think this guy showed bad judgment in this incident and should not be flying an airplane operating under Part 121.